A vaccine to prevent cervical cancer offered strong protection against anal cancer in a large study of women in Costa Rica, adding to evidence that such vaccines can protect against more than just cervical cancer, U.S. researchers said on Monday. The study, conducted by researchers at the National Institutes of Health, involved GlaxoSmithKline's (GSK.L) Cervarix vaccine, which protects against infections triggered by strains 16 and 18 of the human papillomavirus (HPV). "There was strong protection with the vaccine against anal infection," Dr. Aimee Kreimer of the National Cancer Institute, whose study appears in the journal Lancet Oncology, said in a telephone interview.